Which action should the nurse take for a patient diagnosed with an intraocular infection?

Administering the topical antimicrobial agent as ordered is the correct action for a patient diagnosed with an intraocular infection. This step is crucial because intraocular infections, such as endophthalmitis, require prompt treatment to prevent vision loss and to combat the infection effectively. Topical antimicrobial agents help to target the infectious organisms and reduce the inflammation caused by the infection.

The other options may not address the immediate and specific needs of the patient with an intraocular infection. Preparing for enucleation is a severe intervention that is usually considered only after all other treatment options have failed or in cases of severe, irreversible damage. Informing the patient that inflammation will resolve with time could lead to delays in necessary treatment, which could be detrimental in the case of an infection. Testing for HIV may be relevant in certain contexts but does not directly address the urgent needs of managing an intraocular infection and is not typically a first step in treatment.